Key to species of Opeatocerata (females)

(the following species are known only from male specimens: O. agudeloi, O. ampullaria, O. bare, O. chaetohypandrialis, O. cylindrophallus, O. hadrophallus, O. megalophallus, O. mourai, O. nhamunda, O. smithi, O. spinipennis, O. tanimboca and O. zuleideae)

1 Tergites with spots (Figs 58, 74, 179).................................................................... 2

- Tergites without spots (Figs 42, 109, 145)................................................................. 6

2 Tergites with spots on lateral margins (Câmara & Rafael, 2011, figs 17, 18).............. O. melanderi Câmara & Rafael

- Tergites with paramedian spots (Figs 58, 179).............................................................. 3

3 Tergites with paramedian subtriangular spots in dorsal view (Fig. 60)............................... O. cooperi Smith

- Tergites with paramedian subretangular spots in dorsal view (Figs 77, 179)...................................... 4

4 Tergite 10 divided into two subtriangular plates (Fig. 201)............................. O. trilobata Câmara & Rafael

- Tergite 10 undivided (Figs 78, 182)...................................................................... 5

5 Sternite 8 uniformly broad (Fig. 78). Genital fork narrow at base (Fig. 79)....................... O. curvipenis sp. nov.

- Sternite 8 narrow in apical half (Fig. 182). Genital fork wide at base (Fig. 183)....................... O. stubbsi Smith

6 Fore tarsomere 1–5 black (Fig. 47). Sternite 8 with acute apex (Fig. 150)............... O. rubida (Wheeler & Melander)

- Fore tarsomere 4–5 black (Figs 42). Sternite 8 with rounded apex (Figs 44, 111).................................. 7

7 Genital fork with arms fused at apex (Fig. 112).................................................. O. lopesi Smith

- Genital fork with arms not fused at apex (Figs 44, 46)....................................... O. brasiliensis sp. nov.